0 Assigned ID: 610 ----- Attempting Submission 1 (Fri Apr 10 17:43:55 GMT 2015) ----- HST Phase I Proposal 610 (Sombrero_c23.apt) successfully submitted. Receipt: # 610-1 ----- Attempting Submission 2 (Fri Apr 10 23:13:02 GMT 2015) ----- 0 ----- Attempting Submission 1 (Thu Jul 23 17:30:32 GMT 2015) ----- Resolving the Nature of the Stellar Halo of the Sombrero, the Nearest Giant Early-Type Spiral Galaxy Early-type spiral galaxies lie at the apex of the Hubble sequence of galaxies between spirals and ellipticals, and likely play a key role in the morphological and dynamical evolution of galaxies. At a distance of 9 Mpc, the Sombrero (NGC 4594) is the nearest giant early-type spiral galaxy. As such, it is a keystone object for understanding the evolution and early star formation history of such galaxies. Metallicity distribution functions (MDFs) of galaxy halos place important constraints on the hierarchical formation and assembly histories of galaxies. We therefore propose to obtain deep V- and I-band imaging of halo fields in the Sombrero galaxy using WFC3 and ACS in parallel to determine MDFs of individual red giant stars, extending in radius from the outer bulge to the limits of the halo. These data will enable us to address fundamental questions regarding early-type spiral galaxy assembly such as: At what galactocentric radius does the metal-poor field star component start dominating the metal-rich one? How do the radial distributions of metal-poor and metal-rich globular cluster subpopulations compare with those of the halo field stars at the same metallicities? What is the number of massive globular clusters per unit field star for populations of different metallicity? Is there a stellar metallicity gradient in the halo? This is the first such study for any early-type spiral galaxy, and it will provide a new window on the early star formation history of such galaxies, providing unique constraints on the hierarchical assembly scenario. The goal is to measure the metallicity distribution function of RGB stars in the Sombrero galaxy in two fields along the minor axis of its spheroid (bulge), using WFC3/UVIS and ACS/WFC in parallel. Metallicities will be derived from F606W and F814W images. Exposure times were calculated to yield the following at the distance of the Sombrero galaxy: (1) a SNR of 10 for the V-I color at 1 mag beyond the tip of the RGB, and (2) a 5-sigma detection of RGB stars with [Z/H] = -0.2 at the tip of the RGB. We constructed 6 visits of 3 HST orbits each plus one 1-orbit visit. All visits should be performed at the same roll angle, which is chosen to sample a wide range of galactocentric radii with the two cameras. Dithering is performed with several dither points for each filter. RESOLVED STELLAR POPULATIONS 12 false false false false 0.0 0.0 SUPPORTED GALAXY HALO SPIRAL J2000 J2000 WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W ACS/WFC Imaging No No F606W ACS/WFC Imaging No No F814W POS-TARG DITHER 0.308891 LINE false false 3 46.83994 WFC3-UVIS-DITHER-LINE-3PT 2 false POS-TARG DITHER 0.4461326 LINE 0.2718163 false false 79.5438757 4 27.3674389 BOX 3 false /Users/goudfroo/propo/HST/Cycle23/Sombrero/OP-cache/Sombrero_c23_phII-v01.xml Hst Same orient constraint links visits (01 02 03 04 05 06 07) The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. Visit of 3 orbits so as to enhance scheduling flexibility - 1st orbit 3x700 + 310 s, orbit 2 & 3 are 2*1390 s. Using 4-pt dither pattern that works for both WFC3/UVIS and ACS/WFC (Tic-Visit :proposal-id 14175 :visit-id "01" :proposal-version -1 :trans-version "20150609" :date "20-Jul-2015 16:23:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4583760 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14175 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14175 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2884 :al-overhead-at-end 90 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2994 :al-overhead-at-end 65 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2971 :al-overhead-at-end 65 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 3 0 /Users/goudfroo/propo/HST/Cycle23/Sombrero/OP-cache/Sombrero_c23_phII-v02.xml Hst Same orient constraint links visits (01 02 03 04 05 06 07) The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. Visit of 3 orbits so as to enhance scheduling flexibility - 1st orbit 3x700 + 310 s, Using 4-pt dither pattern that works for both WFC3/UVIS and ACS/WFC (Tic-Visit :proposal-id 14175 :visit-id "02" :proposal-version -1 :trans-version "20150609" :date "20-Jul-2015 16:23:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2291888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14175 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14175 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2884 :al-overhead-at-end 90 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 1 0 /Users/goudfroo/propo/HST/Cycle23/Sombrero/OP-cache/Sombrero_c23_phII-v03.xml Hst Same orient constraint links visits (01 02 03 04 05 06 07) The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. Visit of 3 orbits so as to enhance scheduling flexibility - 1st orbit 3x700 + 310 s, orbit 2 & 3 are 2*1400 s. Using 4-pt dither pattern that works for both WFC3/UVIS and ACS/WFC. (Tic-Visit :proposal-id 14175 :visit-id "03" :proposal-version -1 :trans-version "20150609" :date "15-Jul-2015 14:46:14.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4583760 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14175 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14175 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2884 :al-overhead-at-end 90 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 3 0 /Users/goudfroo/propo/HST/Cycle23/Sombrero/OP-cache/Sombrero_c23_phII-v04.xml Hst Same orient constraint links visits (01 02 03 04 05 06 07) The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. Visit of 3 orbits so as to enhance scheduling flexibility - 1st orbit 3x700 + 310 s, orbit 2 & 3 are 2*1400 s. Using 4-pt dither pattern that works for both WFC3/UVIS and ACS/WFC. (Tic-Visit :proposal-id 14175 :visit-id "04" :proposal-version -1 :trans-version "20150609" :date "15-Jul-2015 14:46:16.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4583760 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14175 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14175 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2884 :al-overhead-at-end 90 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "04" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 3 0 /Users/goudfroo/propo/HST/Cycle23/Sombrero/OP-cache/Sombrero_c23_phII-v05.xml Hst Same orient constraint links visits (01 02 03 04 05 06 07) The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. Visit of 3 orbits so as to enhance scheduling flexibility - 1st orbit 3x700 + 310 s, orbit 2 & 3 are 2*1400 s. Using 4-pt dither pattern that works for both WFC3/UVIS and ACS/WFC. (Tic-Visit :proposal-id 14175 :visit-id "05" :proposal-version -1 :trans-version "20150609" :date "15-Jul-2015 14:46:18.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4583760 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14175 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14175 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2884 :al-overhead-at-end 90 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "05" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "05" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 3 0 /private/var/folders/3h/23_s8wz16l1_fq1whjsqqmn000058r/T/OPVisit2704218186286078775.xml Hst Same orient constraint links visits (01 02 03 04 05 06 07) The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. Visit of 3 orbits so as to enhance scheduling flexibility - 1st orbit 3x700 + 310 s, orbit 2 & 3 are 2*1400 s. Using 4-pt dither pattern that works for both WFC3/UVIS and ACS/WFC. (Tic-Visit :proposal-id 14175 :visit-id "06" :proposal-version -1 :trans-version "20150609" :date "23-Jul-2015 13:29:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4583760 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14175 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14175 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2884 :al-overhead-at-end 90 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "06" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "06" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 3 0 /private/var/folders/3h/23_s8wz16l1_fq1whjsqqmn000058r/T/OPVisit518361836419104255.xml Hst Same orient constraint links visits (01 02 03 04 05 06 07) The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. Visit of 3 orbits so as to enhance scheduling flexibility - 1st orbit 3x700 + 310 s, orbit 2 & 3 are 2*1400 s. Using 4-pt dither pattern that works for both WFC3/UVIS and ACS/WFC. (Tic-Visit :proposal-id 14175 :visit-id "07" :proposal-version -1 :trans-version "20150609" :date "23-Jul-2015 13:29:57.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4583760 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14175 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14175 :visit-id "07" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2884 :al-overhead-at-end 90 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "07" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14175 :visit-id "07" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2991 :al-overhead-at-end 65 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 3 0